Project Euler 1 Mystery Cache

Acknowledgements

This cache was inspired by Project Euler.

General notes

• To solve Project Euler puzzles, you will probably have to write a computer program.
• Many of the containers are small, and contain neither pen nor pencil.
• There are explicit finding notes in each geochecker.

The puzzle

If we list all the natural numbers below 10 that are divisible by 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.

Define f(n) as the sum of the multiples of 3 and 5 which are less than n. Thus we can write:
f(10) = 23.

N = f(4720) + f(240) + f(77),

E = f(175) + f(10).

Geochecker